Bat Guano as a Fertilizer
Bat guano has a long, rich history as a prized fertilizer in agriculture, dating back centuries. Its use fell to the wayside with the advent and rise of commercial fertilizer products, but this is once again changing. As more people look for environmentally sustainable or organic gardening products, bat guano is regaining popularity as a naturally occurring, treasured asset.
Why is Bat Guano Good for Plants?
Guano is good for plants because it acts as a plant superfood containing essential nutrients and vitamins, minerals, and microbes, garnered from the bats’ diet. This unique composition offers many benefits to plants beyond traditional nutritional supplementation.
- Bat guano products are rich in N, P, and K. Products vary slightly but typically contain approximately a 10-3-1 ratio.
- Complete range of macronutrients and micronutrients to meet plant needs and prevent “hidden hunger”.
- Slow-release components release nutrients gradually, feeding plants throughout the growing season.
- As a naturally occurring product, it is an effective organic option.
- Doesn’t burn plants like traditional fertilizers because of the lack of chemical salts.
- Improves the soil texture through the addition of organic material and microbes, leading to better drainage, and more extensive root growth.
- Microbes ward off nematodes and other diseases and break down other organic matter in the soil.
Choosing a Bat Guano Fertilizer
When it comes to choosing the best bat guano fertilizer to use on your plants, it’s critical to understand there are two different “types” of products characterized by their nutrient content.
Interestingly enough, the diet eaten by the bat impacts the nutrient content of their excrement. This results in a guano from insect-eating bats having a different concentration of nutrients than guano from fruit-eating bats.
Which bat guano fertilizer should I use, and when?
- Insect-eating bats produce guano that is higher in nitrogen (N). A higher N fertilizer is best to apply during the vegetative phase of plant growth, encouraging healthy, green foliage growth.
- Fruit-eating bats produce guano higher in phosphorus (P). A higher P fertilizer is ideal for use when plants are in the flowering phase when P needs are highest.
Using Bat Guano on Your Plants
Yes, bat guano is technically manure, but unlike other animal manures, it has very little odor, which comes as a relief to any gardener or homeowner who has worked with manure before. A seemingly odorless product makes it easy to use on either indoor or outdoor plants (and continue to live inside your house).
There are four different ways to use bat guano as a fertilizer. Each of these methods can be used on indoor houseplants and outdoor garden or landscape plants and will benefit vegetables, herbs, flowers, all ornamentals, and fruit and nut trees. Two of the methods use the product dry; the other two methods apply a tea made from the guano. As product concentrations vary slightly, make sure to follow the recommended application rate and schedule on the product label.
- Before planting - or filling containers - work the dry bat guano granules or powder into the soil along with compost and bone meal.
- During the growing season, scratch bat guano into the upper part of the soil surface around the base of plants, watering it in well.
- Watered into the soil or applied through an irrigation system as a nutrient-rich tea.
- Apply the bat guano tea as a foliar spray to protect the foliage from pathogens during the growing season.
The use of bat guano as a plant fertilizer is on the upswing again, spurred by a growing awareness of environmental sustainability. As an all natural product it contains a broad spectrum of macro and micronutrients, vitamins, minerals, and microbes to feed plants, improve soil structure, and defend against pests. This plant superfood delivers benefits above and beyond traditional fertilizers!
Products that Contain Nitrogen-heavy Bat Guano:
Products that Contain Phosphorus-heavy Bat Guano:
1. Misra, P., Gautam, N., & Elangovan, V. (2019). Bat guano: a rich source of macro and microelements essential for plant growth. Annals of Plant and Soil Research, 21(1): 82 – 86.
2. Keleher, H. & Sara, A. (1996). Guano: bat’s gift to gardeners. Bats, 14:15-17.
3. Studier, E. H., Sevick, S. H., Ridley, D. M., & Wilson, D. E. (1994). Mineral and nitrogen concen-trations in feces of some neotropical bats. Journal of Mammalogy, 75: 674–680.
4. Goveas, S. W., Miranda, E. C., Seena, S., & Sridhar, K. R. (2006). Observations on guano and bolus of Indian flying fox, Pteropus giganteus. Current Science, 90: 160–162.